Existing switched reluctance motors are in the doubly salient structure, the rotor is formed by laminating silicon steel sheets, with neither winding nor permanent magnet, poles of the stator are wound with exciting windings, the exciting current is input into the stator exciting windings, so that stator salient poles and rotor salient poles interact to produce a torque. The switched reluctance motor operates on the “minimum reluctance principle”, after energizing, the magnetic path has the trend of changing to the minimum reluctance. When the rotor salient poles and stator salient poles are dislocated, the air gap is big, and so is the reluctance; once the stator exciting windings are energized, magnetic pulling force is produced on the rotor salient poles, reducing both the air gap and reluctance in the magnetic path. Meanwhile, a continuous rotating torque can be realized by switching the energizing phase sequence of the stator exciting windings with an electronic switch in a certain logic relation. As there is neither exciting winding nor permanent magnet on the rotor of switched reluctance motor of this structure, the structure is simple and operation is reliable. However, because neither the stator nor the rotor has permanent magnet used for excitation, higher electric excitation power is required to obtain high output torque, therefore the performance to volume ratio of this type of motors is restricted, and there is fairly high driving energy consumption.
Recently many project items of switched reluctance motors for using mixed excitation have emerged, these new technical results have greatly improved and upgraded the performance and application value of switched reluctance motors. However, the structures of this type of motors have not broken the practice of traditional switched reluctance motors wherein the stator housing and rotor iron core are used to form a magnetic path to produce torque, this structure of integral magnetic conduction not only involves long magnetic path and high loss, magnetic interference and flux leakage cannot be avoided between the magnetic salient poles, these factors have affected and hindered the full performance of the excellent properties of switched reluctance motors, and restricted their extensive use. Also, existing switched reluctance motors have the disadvantages of high torque fluctuation and noise, which are unfavorable to the service life of drive parts, in short, the indicators of existing switched reluctance motors, such as output torque, energy consumption and power to volume ratio, are not quite ideal.